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Powered by the Sun: Mirrored Solar Dishes

In the race to develop alternative energy sources, solar power is the undeniable top contender. In addition to being infinitely renewable So much sunlight hits the Earth each day that the world’s entire electricity needs could be met by harvesting only 2% of the solar energy in the Sahara Desert. Of course, this goal has remained elusive due to the problem of costs – both in the manufacture of solar panels and the installation therefor.

But researchers at IBM think they’re one step closer to making solar universally accessible with a low-cost system that can concentrate the sunlight by 2,000 times. The system uses a dish covered in mirrors to aim sunlight in a small area, and which follows the sun throughout the day to catch the most light. Other concentrated solar power systems do the same thing, but a typical system only converts around 20% of the incoming light to usable energy, while this one can convert 80%.

This not only ensures a much larger yield, but also makes the energy it harvests cheap. Bruno Michel, the manager for advanced thermal packaging at IBM Research, believes the design could be three-times cheaper than “comparable” systems. Officially, the estimate he provides claim that the cost per kilowatt hour will work out to less than 10 cents, which works out to 0.01 cents per watt (significantly cheaper than the $0.74 per watt of standard solar).

But as he explains, using simple materials also helps:

The reflective material we use for the mirror facets are similar to that of potato chip bags. The reinforced concrete is also similar to what is being used to build bridges around the world. So outside of the receiver, which contains the photovoltaic chips, we are using standard materials.

A few small high-tech parts will be built in Switzerland (where the prototype is currently being produced). but the main parts of the equipment could easily be built locally, wherever it’s being used. It’s especially well-suited for sunny areas that happen to be dry. As the system runs, it can use excess heat that would normally be wasted to desalinate water. Hence, a large installation could provide not only abundant electricity, but clean drinking water for an entire town.

A combined system of this kind could be an incredible boon to economies in parts of the world that are surrounded by deserts, such as North Africa or Mongolia. But given the increasing risk of worldwide droughts caused by Climate Change, it may also become a necessity in the developed world. Here, such dishes could not only provide clean energy that would reduce our carbon footprint, but also process water for agricultural use, thus combating the problem on two fronts.

IBM researchers are currently working with partners at Airlight Energy, ETH-Zurich, and Interstate University of Applied Sciences Buchs NTB to finish building a large prototype, which they anticipate will be ready by the end of this summer. After testing, they hope to start production at scale within 18 months. Combined with many, many other plans to make panels cheaper and more effective, we can expect to be seeing countless options for solar appearing in the near future.

And if recent years are any indication, we can expect solar usage to double before the year is out.